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MERREM® IV
(meropenem) for Injection, for Intravenous Use
MERREM® IV (meropenem for injection) is a sterile, pyrogen-free, synthetic, carbapenem antibacterial for intravenous administration. It is (4R,5S,6S)-3-[[(3S,5S)-5-(Dimethylcarbamoyl)-3-pyrrolidinyl]thio]-6-[(1R)-1-hydroxyethyl]-4methyl-7-oxo-1-azabicyclo[3.2.0]hept-2-ene-2-carboxylic acid trihydrate. Its empirical formula is C17H25N3O5S•3H2O with a molecular weight of 437.52. Its structural formula is:
 |
MERREM IV is a white to pale yellow crystalline powder. The solution varies from colorless to yellow depending on the concentration. The pH of freshly constituted solutions is between 7.3 and 8.3. Meropenem is soluble in 5% monobasic potassium phosphate solution, sparingly soluble in water, very slightly soluble in hydrated ethanol, and practically insoluble in acetone or ether.
When re-constituted as instructed, each 1 gram MERREM IV vial will deliver 1 gram of meropenem and 90.2 mg of sodium as sodium carbonate (3.92 mEq). Each 500 mg MERREM IV vial will deliver 500 mg meropenem and 45.1 mg of sodium as sodium carbonate (1.96 mEq) [see DOSAGE AND ADMINISTRATION].
MERREM IV is indicated for the treatment of complicated skin and skin structure infections (cSSSI) due to Staphylococcus aureus (methicillin-susceptible isolates only), Streptococcus pyogenes, Streptococcus agalactiae, viridans group streptococci, Enterococcus faecalis (vancomycin-susceptible isolates only), Pseudomonas aeruginosa, Escherichia coli, Proteus mirabilis, Bacteroides fragilis, and Peptostreptococcus species.
MERREM IV is indicated for the treatment of complicated appendicitis and peritonitis caused by viridans group streptococci, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Bacteroides fragilis, B. thetaiotaomicron, and Peptostreptococcus species.
MERREM IV is indicated for the treatment of bacterial meningitis caused by Haemophilus influenzae, Neisseria meningitidis and penicillin-susceptible isolates of Streptococcus pneumoniae.
MERREM IV has been found to be effective in eliminating concurrent bacteremia in association with bacterial meningitis.
To reduce the development of drug-resistant bacteria and maintain the effectiveness of MERREM IV and other antibacterial drugs, MERREM IV should only be used to treat or prevent infections that are proven or strongly suspected to be caused by susceptible bacteria. When culture and susceptibility information are available, they should be considered in selecting or modifying antibacterial therapy. In the absence of such data, local epidemiology and susceptibility patterns may contribute to the empiric selection of therapy.
The recommended dose of MERREM IV is 500 mg given every 8 hours for skin and skin structure infections and 1 gram given every 8 hours for intra-abdominal infections. When treating complicated skin and skin structure infections caused by P. aeruginosa, a dose of 1 gram every 8 hours is recommended.
MERREM IV should be administered by intravenous infusion over approximately 15 minutes to 30 minutes. Doses of 1 gram may also be administered as an intravenous bolus injection (5 mL to 20 mL) over approximately 3 minutes to 5 minutes.
Dosage should be reduced in patients with creatinine clearance of 50 mL/min or less. (See dosing table below.)
When only serum creatinine is available, the following formula (Cockcroft and Gault equation)5 may be used to estimate creatinine clearance.
| Males: | (weight in kg) x (140 – age) |
| (72) x serum creatinine (mg/100 mL) | |
| Females: | (0.85) x (above value) |
Table 1: Recommended MERREM IV Dosage Schedule for Adult Patients with Renal Impairment
| Creatinine Clearance (mL/min) | Dose (dependent on type of infection) | Dosing Interval |
| Greater than 50 | Recommended dose (500 mg cSSSI and 1 gram Intra-abdominal) | Every 8 hours |
| 26-50 | Recommended dose | Every 12 hours |
| 10-25 | One-half recommended dose | Every 12 hours |
| Less than 10 | One-half recommended dose | Every 24 hours |
There is inadequate information regarding the use of MERREM IV in patients on hemodialysis or peritoneal dialysis.
Table 2: Recommended MERREM IV Dosage Schedule for Pediatric Patients 3 Months of Age and Older with Normal Renal Function
| Type of Infection | Dose (mg/kg) | Up to a Maximum Dose | Dosing Interval |
| Complicated skin and skin structure infections | 10 | 500 mg | Every 8 hours |
| Complicated intra-abdominal infections | 20 | 1 gram | Every 8 hours |
| Meningitis | 40 | 2 grams | Every 8 hours |
| There is no experience in pediatric patients with renal impairment. When treating cSSSI caused by P. aeruginosa, a dose of 20 mg/kg (or 1 gram for pediatric patients weighing over 50 kg) every 8 hours is recommended. |
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For pediatric patients (with normal renal function) less than 3 months of age, with complicated intra-abdominal infections, the MERREM IV dose is based on gestational age (GA) and postnatal age (PNA). See dosing table 3 below. MERREM IV should be given as intravenous infusion over 30 minutes.
Table 3: Recommended MERREM IV Dosage Schedule for Pediatric Patients Less than 3 Months of Age with Complicated Intra-abdominal Infections and Normal Renal Function
| Age Group | Dose (mg/kg) | Dose Interval |
| Infants less than 32 weeks GA and PNA less than 2 weeks | 20 | Every 12 hours |
| Infants less than 32 weeks GA and PNA 2 weeks and older | 20 | Every 8 hours |
| Infants 32 weeks and older GA and PNA less than 2 weeks | 20 | Every 8 hours |
| Infants 32 weeks and older GA and PNA 2 weeks and older | 30 | Every 8 hours |
| There is no experience in pediatric patients with renal impairment. | ||
Parenteral drug products should be inspected visually for particulate matter and discoloration prior to administration, whenever solution and container permit.
For Intravenous Bolus Administration
Re-constitute injection vials (500 mg and 1 gram) with sterile Water for Injection (see table 4 below). Shake to dissolve and let stand until clear.
Table 4: Volume of Sterile Water for Injection for Reconstitution of Injection Vials
| Vial Size | Amount of Diluent Added (mL) | Approximate Withdrawable Volume (mL) | Approximate Average Concentration (mg/mL) |
| 500 mg | 10 | 10 | 50 |
| 1 gram | 20 | 20 | 50 |
For Infusion
Compatibility of MERREM IV with other drugs has not been established. MERREM IV should not be mixed with or physically added to solutions containing other drugs.
Freshly prepared solutions of MERREM IV should be used. However, re-constituted solutions of MERREM IV maintain satisfactory potency under the conditions described below. Solutions of intravenous MERREM IV should not be frozen.
MERREM IV injection vials re-constituted with sterile Water for Injection for bolus administration (up to 50 mg/mL of MERREM IV) may be stored for up to 3 hours at up to 25°C (77°F) or for 13 hours at up to 5°C (41°F).
Solutions prepared for infusion (MERREM IV concentrations ranging from 1 mg/mL to 20 mg/mL) re-constituted with Sodium Chloride Injection 0.9% may be stored for 1 hour at up to 25°C (77°F) or 15 hours at up to 5°C (41°F).
Solutions prepared for infusion (MERREM IV concentrations ranging from 1 mg/mL to 20 mg/mL) re-constituted with Dextrose Injection 5% should be used immediately.
Single dose clear glass vials of MERREM IV containing 500 mg or 1 gram (as the trihydrate blended with anhydrous sodium carbonate for re-constitution) of sterile meropenem powder.
MERREM IV is supplied in 20 mL and 30 mL injection vials containing sufficient meropenem to deliver 500 mg or 1 gram for intravenous administration, respectively. The dry powder should be stored at controlled room temperature 20°25°C (68°-77°F) [see USP].
500 mg Injection Vial (NDC 0310-0325-20)
1 gram Injection Vial (NDC 0310-0321-30)
REFERENCES
5. Cockcroft DW, Gault MH. Prediction of creatinine clearance from serum creatinine. Nephron. 1976; 16:31-41.
Distributed by: AstraZeneca Pharmaceuticals LP Wilmington, DE 19850. Revised: Jan 2018
The following are discussed in greater detail in other sections of labeling:
Because clinical trials are conducted under widely varying conditions, adverse reactions rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice.
During clinical investigations, 2904 immunocompetent adult patients were treated for non-CNS infections with MERREM IV (500 mg or 1 gram every 8 hours). Deaths in 5 patients were assessed as possibly related to meropenem; 36 (1.2%) patients had meropenem discontinued because of adverse events. Many patients in these trials were severely ill and had multiple background diseases, physiological impairments and were receiving multiple other drug therapies. In the seriously ill patient population, it was not possible to determine the relationship between observed adverse events and therapy with MERREM IV.
The following adverse reaction frequencies were derived from the clinical trials in the 2904 patients treated with MERREM IV.
Local adverse events that were reported with MERREM IV were as follows:
| Inflammation at the injection site | 2.4% |
| Injection site reaction | 0.9% |
| Phlebitis/thrombophlebitis | 0.8% |
| Pain at the injection site | 0.4% |
| Edema at the injection site | 0.2% |
Systemic adverse events that were reported with MERREM IV occurring in greater than 1.0% of the patients were diarrhea (4.8%), nausea/vomiting (3.6%), headache (2.3%), rash (1.9%), sepsis (1.6%), constipation (1.4%), apnea (1.3%), shock (1.2%), and pruritus (1.2%).
Additional systemic adverse events that were reported with MERREM IV and occurring in less than or equal to 1.0% but greater than 0.1% of the patients are listed below within each body system in order of decreasing frequency:
Bleeding events were seen as follows: gastrointestinal hemorrhage (0.5%), melena (0.3%), epistaxis (0.2%), hemoperitoneum (0.2%).
Body as a Whole: pain, abdominal pain, chest pain, fever, back pain, abdominal enlargement, chills, pelvic pain
Cardiovascular: heart failure, heart arrest, tachycardia, hypertension, myocardial infarction, pulmonary embolus, bradycardia, hypotension, syncope
Digestive System: oral moniliasis, anorexia, cholestatic jaundice/jaundice, flatulence, ileus, hepatic failure, dyspepsia, intestinal obstruction
Hemic/Lymphatic: anemia, hypochromic anemia, hypervolemia
Metabolic/Nutritional: peripheral edema, hypoxia
Nervous System: insomnia, agitation, delirium, confusion, dizziness, seizure, nervousness, paresthesia, hallucinations, somnolence, anxiety, depression, asthenia [see WARNINGS AND PRECAUTIONS]
Respiratory: respiratory disorder, dyspnea, pleural effusion, asthma, cough increased, lung edema
Skin and Appendages: urticaria, sweating, skin ulcer
Urogenital System: dysuria, kidney failure, vaginal moniliasis, urinary incontinence
Adverse laboratory changes that were reported and occurring in greater than 0.2% of the patients were as follows:
Hepatic: increased alanine transaminase (ALT), aspartate transaminase (AST), alkaline phosphatase, lactate dehydrogenase (LDH), and bilirubin
Hematologic: increased platelets, increased eosinophils, decreased platelets, decreased hemoglobin, decreased hematocrit, decreased white blood cell (WBC), shortened prothrombin time and shortened partial thromboplastin time, leukocytosis, hypokalemia
Renal: increased creatinine and increased blood urea nitrogen (BUN)
Urinalysis: presence of red blood cells
In a study of complicated skin and skin structure infections, the adverse reactions were similar to those listed above. The most common adverse events occurring in greater than 5% of the patients were: headache (7.8%), nausea (7.8%), constipation (7.0%), diarrhea (7.0%), anemia (5.5%), and pain (5.1%). Adverse events with an incidence of greater than 1%, and not listed above, include: pharyngitis, accidental injury, gastrointestinal disorder, hypoglycemia, peripheral vascular disorder, and pneumonia.
For patients with varying degrees of renal impairment, the incidence of heart failure, kidney failure, seizure and shock reported with MERREM IV, increased in patients with moderately severe renal impairment (creatinine clearance 10 to 26 mL/min) [see DOSAGE AND ADMINISTRATION , WARNINGS AND PRECAUTIONS, Use In Specific Population and CLINICAL PHARMACOLOG].
Pediatric Patients with Serious Bacterial Infections (excluding Bacterial Meningitis):
MERREM IV was studied in 515 pediatric patients (3 months to less than 13 years of age) with serious bacterial infections (excluding meningitis, see next section) at dosages of 10 mg/kg to 20 mg/kg every 8 hours. The types of systemic and local adverse events seen in these patients are similar to the adults, with the most common adverse events reported as possibly, probably, or definitely related to MERREM IV and their rates of occurrence as follows:
| Diarrhea | 3.5% |
| Rash | 1.6% |
| Nausea and Vomiting | 0.8% |
Pediatric Patients with Bacterial Meningitis:
MERREM IV was studied in 321 pediatric patients (3 months to less than 17 years of age) with meningitis at a dosage of 40 mg/kg every 8 hours. The types of systemic and local adverse events seen in these patients are similar to the adults, with the most common adverse reactions reported as possibly, probably, or definitely related to MERREM IV and their rates of occurrence as follows:
| Diarrhea | 4.7% |
| Rash (mostly diaper area moniliasis) | 3.1% |
| Oral Moniliasis | 1.9% |
| Glossitis | 1.0% |
In the meningitis studies, the rates of seizure activity during therapy were comparable between patients with no CNS abnormalities who received meropenem and those who received comparator agents (either cefotaxime or ceftriaxone). In the MERREM IV treated group, 12/15 patients with seizures had late onset seizures (defined as occurring on day 3 or later) versus 7/20 in the comparator arm. The meropenem group had a statistically higher number of patients with transient elevation of liver enzymes.
Pediatric Patients (Neonates and Infants less than 3 months of Age):
MERREM IV was studied in 200 neonates and infants less than 3 months of age. The study was open-label, uncontrolled, 98% of the infants received concomitant medications, and the majority of adverse events were reported in neonates less than 32 weeks gestational age and critically ill at baseline, making it difficult to assess the relationship of the adverse events to MERREM IV.
The adverse reactions seen in these patients that were reported and their rates of occurrence are as follows:
| Convulsion | 5.0% |
| Hyperbilirubinemia (conjugated) | 4.5% |
| Vomiting | 2.5% |
Laboratory changes seen in the pediatric studies, including the meningitis studies, were similar to those reported in the adult studies.
The following adverse reactions have been identified during post-approval use of MERREM IV. Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure.
Worldwide post-marketing adverse reactions not otherwise listed in the Adverse Reactions from Clinical Trials section of this prescribing information and reported as possibly, probably, or definitely drug related are listed within each body system in order of decreasing severity.
Blood and Lymphatic System Disorders: agranulocytosis, neutropenia, and leukopenia; a positive direct or indirect Coombs test, and hemolytic anemia.
Immune System Disorders: angioedema and drug rash with eosinophilia and systemic symptoms (DRESS syndrome).
Skin and Subcutaneous Disorders: toxic epidermal necrolysis, Stevens-Johnson syndrome, and erythema multiforme.
Probenecid competes with meropenem for active tubular secretion, resulting in increased plasma concentrations of meropenem. Co-administration of probenecid with meropenem is not recommended.
Case reports in the literature have shown that co-administration of carbapenems, including meropenem, to patients receiving valproic acid or divalproex sodium results in a reduction in valproic acid concentrations. The valproic acid concentrations may drop below the therapeutic range as a result of this interaction, therefore increasing the risk of breakthrough seizures. Although the mechanism of this interaction is unknown, data from in vitro and animal studies suggest that carbapenems may inhibit the hydrolysis of valproic acid's glucuronide metabolite (VPA-g) back to valproic acid, thus decreasing the serum concentrations of valproic acid. If administration of MERREM IV is necessary, then supplemental anti-convulsant therapy should be considered [see WARNINGS AND PRECAUTIONS].
Included as part of the "PRECAUTIONS" Section
Serious and occasionally fatal hypersensitivity (anaphylactic) reactions have been reported in patients receiving therapy with β-lactams. These reactions are more likely to occur in individuals with a history of sensitivity to multiple allergens.
There have been reports of individuals with a history of penicillin hypersensitivity who have experienced severe hypersensitivity reactions when treated with another β-lactam. Before initiating therapy with MERREM IV, it is important to inquire about previous hypersensitivity reactions to penicillins, cephalosporins, other β-lactams, and other allergens. If an allergic reaction to MERREM IV occurs, discontinue the drug immediately.
Seizures and other adverse CNS experiences have been reported during treatment with MERREM IV These experiences have occurred most commonly in patients with CNS disorders (e.g., brain lesions or history of seizures) or with bacterial meningitis and/or compromised renal function [see ADVERSE REACTIONS and DRUG INTERACTIONS].
During clinical investigations, 2904 immunocompetent adult patients were treated for non-CNS infections with the overall seizure rate being 0.7% (based on 20 patients with this adverse event). All meropenem-treated patients with seizures had pre-existing contributing factors. Among these are included prior history of seizures or CNS abnormality and concomitant medications with seizure potential. Dosage adjustment is recommended in patients with advanced age and/or adult patients with creatinine clearance of 50 mL/min or less [see DOSAGE AND ADMINISTRATION].
Close adherence to the recommended dosage regimens is urged, especially in patients with known factors that predispose to convulsive activity. Continue anti-convulsant therapy in patients with known seizure disorders. If focal tremors, myoclonus, or seizures occur, evaluate neurologically, placed on anti-convulsant therapy if not already instituted, and reexamine the dosage of MERREM IV to determine whether it should be decreased or discontinued.
The concomitant use of meropenem and valproic acid or divalproex sodium is generally not recommended. Case reports in the literature have shown that co-administration of carbapenems, including meropenem, to patients receiving valproic acid or divalproex sodium results in a reduction in valproic acid concentrations. The valproic acid concentrations may drop below the therapeutic range as a result of this interaction, therefore increasing the risk of breakthrough seizures. Increasing the dose of valproic acid or divalproex sodium may not be sufficient to overcome this interaction. Consider administration of antibacterial drugs other than carbapenems to treat infections in patients whose seizures are well controlled on valproic acid or divalproex sodium. If administration of MERREM IV is necessary, consider supplemental anti-convulsant therapy [see DRUG INTERACTIONS].
Clostridium difficile-associated diarrhea (CDAD) has been reported with use of nearly all antibacterial agents, including MERREM IV, and may range in severity from mild diarrhea to fatal colitis. Treatment with antibacterial agents alters the normal flora of the colon leading to overgrowth of C. difficile.
C. difficile produces toxins A and B which contribute to the development of CDAD. Hypertoxin producing isolates of C. difficile cause increased morbidity and mortality, as these infections can be refractory to antimicrobial therapy and may require colectomy. CDAD must be considered in all patients who present with diarrhea following antibacterial drug use. Careful medical history is necessary since CDAD has been reported to occur over two months after the administration of antibacterial agents.
If CDAD is suspected or confirmed, ongoing antibacterial drug use not directed against C. difficile may need to be discontinued. Appropriate fluid and electrolyte management, protein supplementation, antibacterial drug treatment of C. difficile, and surgical evaluation should be instituted as clinically indicated.
Prescribing MERREM IV in the absence of a proven or strongly suspected bacterial infection or a prophylactic indication is unlikely to provide benefit to the patient and increases the risk of the development of drug-resistant bacteria.
As with other broad-spectrum antibacterial drugs, prolonged use of meropenem may result in overgrowth of nonsusceptible organisms. Repeated evaluation of the patient is essential. If superinfection does occur during therapy, appropriate measures should be taken.
In patients with renal impairment, thrombocytopenia has been observed but no clinical bleeding reported [see DOSAGE AND ADMINISTRATION, ADVERSE REACTIONS, Use In Specific Populations, and CLINICAL PHARMACOLOGY].
Alert patients receiving MERREM IV on an outpatient basis regarding adverse events such as seizures, delirium, headaches and/or paresthesias that could interfere with mental alertness and/or cause motor impairment. Until it is reasonably well established that MERREM IV is well tolerated, advise patients not to operate machinery or motorized vehicles [see ADVERSE REACTIONS].
Carcinogenesis studies have not been performed.
Genetic toxicity studies were performed with meropenem using the bacterial reverse mutation test, the Chinese hamster ovary HGPRT assay, cultured human lymphocytes cytogenic assay, and the mouse micronucleus test. There was no evidence of mutagenic potential found in any of these tests.
Reproductive studies were performed with meropenem in rats at doses up to 1000 mg/kg/day, and cynomolgus monkeys at doses up to 360 mg/kg/day (on the basis of AUC comparisons, approximately 1.8 times and 3.7 times, respectively, to the human exposure at the usual dose of 1 gram every 8 hours). There was no reproductive toxicity seen.
There are no adequate and well-controlled studies with meropenem in pregnant women. Because animal reproduction studies are not always predictive of human response, this drug should be used during pregnancy only if clearly needed.
Reproductive studies have been performed with meropenem in rats at doses of up to 1000 mg/kg/day, and cynomolgus monkeys at doses of up to 360 mg/kg/day (on the basis of AUC comparisons, approximately 1.8 times and 3.7 times higher, respectively, than human exposure at the usual dose of 1 gram every 8 hours). These studies revealed no evidence of impaired fertility or harm to the fetus due to meropenem, although there were slight changes in fetal body weight at doses of 250 mg/kg/day (on the basis of AUC comparisons, 0.4 times the human exposure at a dose of 1 gram every 8 hours) and above in rats.
Meropenem has been reported to be excreted in human milk. Caution should be exercised when MERREM IV is administered to a nursing woman.
The safety and effectiveness of MERREM IV have been established for pediatric patients 3 months of age and older with complicated skin and skin structure infections and bacterial meningitis, and for pediatric patients of all ages with complicated intra-abdominal infections.
Use of MERREM IV in pediatric patients 3 months of age and older with complicated skin and skin structure infections is supported by evidence from an adequate and well-controlled study in adults and additional data from pediatric pharmacokinetics studies [see INDICATIONS, DOSAGE AND ADMINISTRATION, ADVERSE REACTIONS, CLINICAL PHARMACOLOGY and Clinical Studies].
Use of MERREM IV in pediatric patients 3 months of age and older with intra-abdominal infections is supported by evidence from adequate and well-controlled studies in adults with additional data from pediatric pharmacokinetics studies and controlled clinical trials in pediatric patients. Use of MERREM IV in pediatric patients less than 3 months of age with intra-abdominal infections is supported by evidence from adequate and well-controlled studies in adults with additional data from a pediatric pharmacokinetic and safety study [see INDICATIONS, DOSAGE AND ADMINISTRATION, ADVERSE REACTIONS, CLINICAL PHARMACOLOGY and Clinical Studies].
Use of MERREM IV in pediatric patients 3 months of age and older with bacterial meningitis is supported by evidence from adequate and well-controlled studies in the pediatric population [see INDICATIONS, DOSAGE AND ADMINISTRATION, ADVERSE REACTIONS, CLINICAL PHARMACOLOGY and Clinical Studies].
Of the total number of subjects in clinical studies of MERREM IV, approximately 1100 (30%) were 65 years of age and older, while 400 (11%) were 75 years and older. Additionally, in a study of 511 patients with complicated skin and skin structure infections, 93 (18%) were 65 years of age and older, while 38 (7%) were 75 years and older. No overall differences in safety or effectiveness were observed between these subjects and younger subjects; spontaneous reports and other reported clinical experience have not identified differences in responses between the elderly and younger patients, but greater sensitivity of some older individuals cannot be ruled out.
Meropenem is known to be substantially excreted by the kidney, and the risk of adverse reactions to this drug may be greater in patients with renal impairment. Because elderly patients are more likely to have decreased renal function, care should be taken in dose selection, and it may be useful to monitor renal function.
A pharmacokinetic study with MERREM IV in elderly patients has shown a reduction in the plasma clearance of meropenem that correlates with age-associated reduction in creatinine clearance [see CLINICAL PHARMACOLOGY].
Dosage adjustment is necessary in patients with creatinine clearance 50 mL/min or less [see DOSAGE AND ADMINISTRATION, WARNINGS AND PRECAUTIONS, and CLINICAL PHARMACOLOGY].
In mice and rats, large intravenous doses of meropenem (2200 mg/kg to 4000 mg/kg) have been associated with ataxia, dyspnea, convulsions, and mortalities.
Intentional overdosing of MERREM IV is unlikely, although accidental overdosing might occur if large doses are given to patients with reduced renal function. The largest dose of meropenem administered in clinical trials has been 2 grams given intravenously every 8 hours. At this dosage, no adverse pharmacological effects or increased safety risks have been observed.
Limited postmarketing experience indicates that if adverse events occur following overdosage, they are consistent with the adverse event profile described in the Adverse Reactions section and are generally mild in severity and resolve on withdrawal or dose reduction. Consider symptomatic treatments. In individuals with normal renal function, rapid renal elimination takes place. Meropenem and its metabolite are readily dialyzable and effectively removed by hemodialysis; however, no information is available on the use of hemodialysis to treat overdosage.
MERREM IV is contraindicated in patients with known hypersensitivity to any component of this product or to other drugs in the same class or in patients who have demonstrated anaphylactic reactions to beta (β)-lactams.
Meropenem is an antibacterial drug [see Microbiology]
At the end of a 30-minute intravenous infusion of a single dose of MERREM IV in healthy volunteers, mean peak plasma concentrations of meropenem are approximately 23 mcg/mL (range 14-26) for the 500 mg dose and 49 mcg/mL (range 39-58) for the 1 gram dose. A 5-minute intravenous bolus injection of MERREM IV in healthy volunteers results in mean peak plasma concentrations of approximately 45 mcg/mL (range 18-65) for the 500 mg dose and 112 mcg/mL (range 83140) for the 1 gram dose.
Following intravenous doses of 500 mg, mean plasma concentrations of meropenem usually decline to approximately 1 mcg/mL at 6 hours after administration.
No accumulation of meropenem in plasma was observed with regimens using 500 mg administered every 8 hours or 1 gram administered every 6 hours in healthy volunteers with normal renal function.
Distribution
The plasma protein binding of meropenem is approximately 2%.
After a single intravenous dose of MERREM IV, the highest mean concentrations of meropenem were found in tissues and fluids at 1 hour (0.5 hours to 1.5 hours) after the start of infusion, except where indicated in the tissues and fluids listed in Table 5 below.
Table 5: Meropenem Concentrations in Selected Tissues (Highest Concentrations Reported)
| Tissue | Intravenous. Dose (gram) | Number of Samples | Mean [μg/mL or mcg/(gram)]1 | Range [μg/mL or mcg/(gram)] |
| Endometrium | 0.5 | 7 | 4.2 | 1.7-10.2 |
| Myometrium | 0.5 | 15 | 3.8 | 0.4-8.1 |
| Ovary | 0.5 | 8 | 2.8 | 0.8-4.8 |
| Cervix | 0.5 | 2 | 7 | 5.4-8.5 |
| Fallopian tube | 0.5 | 9 | 1.7 | 0.3-3.4 |
| Skin | 0.5 | 22 | 3.3 | 0.5-12.6 |
| Interstitial fluid2 | 0.5 | 9 | 5.5 | 3.2-8.6 |
| Skin | 1 | 10 | 5.3 | 1.3-16.7 |
| Interstitial fluid2 | 1 | 5 | 26.3 | 20.9-37.4 |
| Colon | 1 | 2 | 2.6 | 2.5-2.7 |
| Bile | 1 | 7 | 14.6 (3 hours) | 4-25.7 |
| Gall bladder | 1 | 1 | - | 3.9 |
| Peritoneal fluid | 1 | 9 | 30.2 | 7.4-54.6 |
| Lung | 1 | 2 | 4.8 (2 hours) | 1.4-8.2 |
| Bronchial mucosa | 1 | 7 | 4.5 | 1.3-11.1 |
| Muscle | 1 | 2 | 6.1 (2 hours) | 5.3-6.9 |
| Fascia | 1 | 9 | 8.8 | 1.5-20 |
| Heart valves | 1 | 7 | 9.7 | 6.4-12.1 |
| Myocardium | 1 | 10 | 15.5 | 5.2-25.5 |
| CSF (inflamed) | 20 mg/kg3 | 8 | 1.1 (2 hours) | 0.2-2.8 |
| 40 mg/kg4 | 5 | 3.3 (3 hours) | 0.9-6.5 | |
| CSF (uninflamed) | 1 | 4 | 0.2 (2 hours) | 0.1-0.3 |
| 1. at 1 hour unless otherwise noted 2. obtained from blister fluid 3.in pediatric patients of age 5 months to 8 years 4. in pediatric patients of age 1 month to 15 years |
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Metabolism
There is one metabolite of meropenem that is microbiologically inactive.
Excretion
In subjects with normal renal function, the elimination half-life of meropenem is approximately 1 hour.
Meropenem is primarily excreted unchanged by the kidneys. Approximately 70% (50% - 75%) of the dose is excreted unchanged within 12 hours. A further 28% is recovered as the microbiologically inactive metabolite. Fecal elimination represents only approximately 2% of the dose. The measured renal clearance and the effect of probenecid show that meropenem undergoes both filtration and tubular secretion.
Urinary concentrations of meropenem in excess of 10 mcg/mL are maintained for up to 5 hours after a 500 mg dose.
Pharmacokinetic studies with MERREM IV in patients with renal impairment have shown that the plasma clearance of meropenem correlates with creatinine clearance. Dosage adjustments are necessary in subjects with renal impairment (creatinine clearance 50 mL/min or less) [see DOSAGE AND ADMINISTRATION and Use In Specific Populations].
Meropenem IV is hemodialyzable. However, there is no information on the usefulness of hemodialysis to treat overdosage [see OVERDOSE].
A pharmacokinetic study with MERREM IV in patients with hepatic impairment has shown no effects of liver disease on the pharmacokinetics of meropenem.
A pharmacokinetic study with MERREM IV in elderly patients with renal impairment showed a reduction in plasma clearance of meropenem that correlates with age-associated reduction in creatinine clearance.
The pharmacokinetics of meropenem for injection IV, in pediatric patients 2 years of age or older, are similar to those in adults. The elimination half-life for meropenem was approximately 1.5 hours in pediatric patients of age 3 months to 2 years.
The pharmacokinetics of meropenem in patients less than 3 months of age receiving combination antibacterial drug therapy are given below.
Table 6: Meropenem Pharmacokinetic Parameters in Patients Less Than 3 Months of Age*
| GA less than 32 weeks PNA less than 2 weeks (20mg/kg every 12 hours) | GA less than 32 weeks PNA 2 weeks or older (20mg/kg every 8 hours) | GA 32 weeks or older PNA less than 2 weeks (20mg/kg every 8 hours) | GA 32 weeks or older PNA 2 weeks or older (30mg/kg every 8 hours) | Overall | |
| CL (L/h/kg) | 0.089 | 0.122 | 0.135 | 0.202 | 0.119 |
| V (L/kg) | 0.489 | 0.467 | 0.463 | 0.451 | 0.468 |
| AUC0-24 (mcg-h/mL) | 448 | 491 | 445 | 444 | 467 |
| Cmax (mcg/mL) | 44.3 | 46.5 | 44.9 | 61 | 46.9 |
| Cmin (mcg/mL) | 5.36 | 6.65 | 4.84 | 2.1 | 5.65 |
| T1/2 (h) | 3.82 | 2.68 | 2.33 | 1.58 | 2.68 |
| *Values are derived from a population pharmacokinetic analysis of sparse data | |||||
Probenecid competes with meropenem for active tubular secretion and thus inhibits the renal excretion of meropenem. Following administration of probenecid with meropenem, the mean systemic exposure increased 56% and the mean elimination half-life increased 38%. Co-administration of probenecid with meropenem is not recommended.
The bactericidal activity of meropenem results from the inhibition of cell wall synthesis. Meropenem penetrates the cell wall of most gram-positive and gram-negative bacteria to bind penicillin-binding-protein (PBP) targets. Meropenem binds to PBPs 2, 3 and 4 of Escherichia coli and Pseudomonas aeruginosa; and PBPs 1, 2 and 4 of Staphylococcus aureus. Bactericidal concentrations (defined as a 3 log10 reduction in cell counts within 12 hours to 24 hours) are typically 1-2 times the bacteriostatic concentrations of meropenem, with the exception of Listeria monocytogenes, against which lethal activity is not observed.
Meropenem does not have in vitro activity against methicillin-resistant Staphylococcus aureus (MRSA) or methicillin-resistant Staphylococcus epidermidis (MRSE).
There are several mechanisms of resistance to carbapenems: 1) decreased permeability of the outer membrane of gram-negative bacteria (due to diminished production of porins) causing reduced bacterial uptake, 2) reduced affinity of the target PBPs, 3) increased expression of efflux pump components, and 4) production of antibacterial drug-destroying enzymes (carbapenemases, metallo-β-lactamases).
Cross-resistance is sometimes observed with isolates resistant to other carbapenems.
In vitro tests show meropenem to act synergistically with aminoglycoside antibacterial drugs against some isolates of Pseudomonas aeruginosa.
Meropenem has been shown to be active against most isolates of the following microorganisms, both in vitro and in clinical infections [see INDICATIONS].
Enterococcus faecalis (vancomycin-susceptible isolates only)
Staphylococcus aureus (methicillin-susceptible isolates only)
Streptococcus agalactiae
Streptococcus pneumoniae (penicillin-susceptible isolates only)
Streptococcus pyogenes
Viridans group streptococci
Escherichia coli
Haemophilus influenzae
Klebsiella pneumoniae
Neisseria meningitidis
Proteus mirabilis
Pseudomonas aeruginosa
Bacteroides fragilis
Bacteroides thetaiotaomicron
Peptostreptococcus species
The following in vitro data are available, but their clinical significance is unknown. At least 90% of the following bacteria exhibit an in vitro minimum inhibitory concentration (MIC) less than or equal to the susceptible breakpoint for meropenem against isolates of similar genus or organism group. However, the efficacy of meropenem in treating clinical infections caused by these bacteria have not been established in adequate and well-controlled clinical trials.
Staphylococcus epidermidis (methicillin-susceptible isolates only)
Aeromonas hydrophila
Campylobacter jejuni
Citrobacter freundii
Citrobacter koseri
Enterobacter cloacae
Hafnia alvei
Klebsiella oxytoca
Moraxella catarrhalis
Morganella morganii
Pasteurella multocida
Proteus vulgaris
Serratia marcescens
Bacteroides ovatus
Bacteroides uniformis
Bacteroides ureolyticus
Bacteroides vulgatus
Clostridium difficile
Clostridium perfringens
Eggerthella lenta
Fusobacterium species
Parabacteroides distasonis
Porphyromonas asaccharolytica
Prevotella bivia
Prevotella intermedia
Prevotella melaninogenica
Propionibacterium acnes
When available, the clinical microbiology laboratory should provide cumulative reports of in vitro susceptibility test results for antimicrobial drugs used in local hospitals and practice areas as periodic reports that describe the susceptibility profile of nosocomial and community-acquired pathogens. These reports should aid in the selection of an appropriate antibacterial drug for treatment.
Quantitative methods are used to determine antimicrobial MICs. These MICs provide estimates of the susceptibility of bacteria to antimicrobial compounds. The MICs should be determined using a standardized test method (broth or agar).1,3 The MIC values should be interpreted according to the criteria provided in Table 7.
Quantitative methods that require measurement of zone diameters can also provide reproducible estimates of the susceptibility of bacteria to antimicrobial compounds. The zone size should be determined using a standardized test method.2,3 This procedure uses paper disks impregnated with 10-mcg of meropenem to test the susceptibility of bacteria to meropenem. The disk diffusion breakpoints are provided in Table 7.
For anaerobic bacteria, the susceptibility to meropenem can be determined by a standardized test method.2,4 The MIC values obtained should be interpreted according to the criteria provided in Table 7.
Table 7: Susceptibility Test Interpretive Criteria for Meropenem
| Minimum Inhibitory Concentrations (mcg/mL) | Disk Diffusion (zone diameters in mm) |
|||||
| Pathogen | S | I | R | S | I | R |
| Enterobacteriaceae | ≤ 1 | 2 | ≥ 4 | ≥ 23 | 20-22 | ≤ 19 |
| Pseudomonas aeruginosaa | ≤ 2 | 4 | ≥ 8 | ≥ 19 | 16-18 | ≤ 15 |
| Haemophilus influenzaeb | ≤ 0.5 | - | - | ≥ 20 | - | - |
| Neisseria meningitidisb | ≤ 0.25 | - | - | ≥ 30 | - | - |
| Streptococcus pneumoniae c,d | ≤ 0.25 | 0.5 | ≥ 1 | - | - | - |
| Streptococcus agalactiae and Streptococcus pyogenes b,d | ≤ 0.5 | - | - | - | - | - |
| Viridans group streptococcib,d | ≤ 0.5 | - | - | - | - | - |
| Anaerobese | ≤ 4 | 8 | ≥ 16 | - | - | - |
| S = Susceptible, I = Intermediate, R = Resistant No interpretative criteria have been established for testing enterococci. Susceptibility of staphylococci to meropenem may be deduced from testing either cefoxitin or oxacillin. a The interpretive criteria for P. aeruginosa are based upon the dosing of 1g every 8 hours. b The current absence of data on resistant isolates precludes defining any category other than “Susceptible”. If isolates yield MIC results other than susceptible, they should be submitted to a reference laboratory for additional testing. c For nonmeningitis isolates of S. pneumoniae a penicillin MIC of ≤ 0.06 mcg/mL or oxacillin zone ≥ 20 mm can predict susceptibility to meropenem. MIC testing should be performed on isolates that do not test as susceptible by either of these methods, and on all meningitis S. pneumoniae isolates. d Reliable disk diffusion tests for meropenem do not yet exist for testing streptococci. e MIC values using either Brucella blood or Wilkins Chalgren agar (former reference medium) are considered equivalent, Broth microdilution is only recommended for testing the B. fragilis group. MIC values for agar or broth microdilution are considered equivalent for that group. |
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A report of Susceptible indicates that the antimicrobial drug is likely to inhibit growth of the pathogen if the antimicrobial drug reaches the concentration usually achievable at the site of infection. A report of Intermediate indicates that the result should be considered equivocal, and, if the microorganism is not fully susceptible to alternative, clinically feasible drugs, the test should be repeated. This category implies possible clinical applicability in body sites where the drug is physiologically concentrated or in situations where a high dosage of drug can be used. This category also provides a buffer zone that prevents small uncontrolled technical factors from causing major discrepancies in interpretation. A report of Resistant indicates that the antimicrobial drug is not likely to inhibit growth of the pathogen if the antimicrobial drug reaches concentrations usually achievable at the infection site; other therapy should be selected.
Standardized susceptibility test procedures require the use of laboratory controls to monitor and ensure the accuracy and precision of supplies and reagents used in the assay, and the techniques of the individuals performing the test.1,2,3,4 Standard meropenem powder should provide the following range of MIC values noted in Table 8. For the diffusion technique using the 10-mcg meropenem disk, the criteria in Table 8 should be achieved.
Table 8: Acceptable Quality Control Ranges for Meropenem
| Quality Control Strain | Minimum Inhibitory Concentrations (mcg/mL) |
Disk Diffusion (Zone diameters in mm) |
| Staphylococcus aureus ATCC 29213 | 0.03-0.12 | - |
| Staphylococcus aureus ATCC 25923 | - | 29-37 |
| Streptococcus pneumoniae ATCC 49619 | 0.03-0.25 | 28-35 |
| Enterococcus faecalis ATCC 29212 | 2-8 | |
| Escherichia coli ATCC 25922 | 0.008-0.06 | 28-35 |
| Haemophilus influenzae ATCC 49766 | 0.03-0.12 | |
| Haemophilus influenzae ATCC 49247 | - | 20-28 |
| Pseudomonas aeruginosa ATCC 27853 | 0.12-1 | 27-33 |
| Bacteroides fragilis1 ATCC 25285 | 0.03-0.25 | |
| Bacteroides thetaiotaomicron1 ATCC 29741 | 0.125-0.5 | |
| Eggerthella lenta1 ATCC 43055 | 0.125-1 | |
| Clostridium difficile1 ATCC 700057 | 0.5-4 | |
| 1. Using the Reference Agar Dilution procedure. ATCC=American Type Culture Collection | ||
Adult patients with complicated skin and skin structure infections including complicated cellulitis, complex abscesses, perirectal abscesses, and skin infections requiring intravenous antimicrobials, hospitalization, and surgical intervention were enrolled in a randomized, multi-center, international, double-blind trial. The study evaluated meropenem at doses of 500 mg administered intravenously every 8 hours and imipenem-cilastatin at doses of 500 mg administered intravenously every 8 hours. The study compared the clinical response between treatment groups in the clinically evaluable population at the follow-up visit (test-of-cure). The trial was conducted in the United States, South Africa, Canada, and Brazil. At enrollment, approximately 37% of the patients had underlying diabetes, 12% had underlying peripheral vascular disease and 67% had a surgical intervention. The study included 510 patients randomized to meropenem and 527 patients randomized to imipenem-cilastatin. Two hundred and sixty one (261) patients randomized to meropenem and 287 patients randomized to imipenem-cilastatin were clinically evaluable. The success rates in the clinically evaluable patients at the follow-up visit were 86% (225/261) in the meropenem arm and 83% (238/287) in imipenem-cilastatin arm.
The success rates for the clinically evaluable population are provided in Table 9.
Table 9: Success Rates at Test-of-Cure Visit for Clinically Evaluable Population with Complicated Skin and Skin Structure Infections
| Population | MERREM IV n1/N2 (%) |
Imipenem-cilastatin n1/N2 (%) |
| Total | 225/261 (86) | 238/287 (83) |
| Diabetes mellitus | 83/97 (86) | 76/105 (72) |
| No diabetes mellitus | 142/164 (87) | 162/182 (89) |
| Less than 65 years of age | 190/218 (87) | 205/241 (85) |
| 65 years of age or older | 35/43 (81) | 33/46 (72) |
| Men | 130/148 (88) | 137/172 (80) |
| Women | 95/113 (84) | 101/115 (88) |
| 1.
n=number of patients with satisfactory response. 2. N=number of patients in the clinically evaluable population or respective subgroup within treatment groups. |
||
The clinical efficacy rates by pathogen are provided in Table 10. The values represent the number of patients clinically cured/number of clinically evaluable patients at the post-treatment follow-up visit, with the percent cure in parentheses (Fully Evaluable analysis set).
Table 10: Clinical Efficacy Rates by Pathogen for Clinically Evaluable Population
| MICROORGANISMS1 | MERREM IV n2/N3 (%)4 |
Imipenem-cilastatin n2/N3 (%)4 |
| Gram-positive aerobes | ||
| Staphylococcus aureus, methicillin susceptible | 82/88 (93) | 84/100 (84) |
| Streptococcus pyogenes (Group A) | 26/29 (90) | 28/32 (88) |
| Streptococcus agalactiae (Group B) | 12/17 (71) | 16/19 (84) |
| Enterococcus faecalis | 9/12 (75) | 14/20 (70) |
| Viridans group streptococci | 11/12 (92) | 5/6 (83) |
| Gram-negative aerobes | ||
| Escherichia coli | 12/15 (80) | 15/21 (71) |
| Pseudomonas aeruginosa | 11/15 (73) | 13/15 (87) |
| Proteus mirabilis | 11/13 (85) | 6/7 (86) |
| Anaerobes | ||
| Bacteroides fragilis | 10/11 (91) | 9/10 (90) |
| Peptostreptococcus Species | 10/13 (77) | 14/16 (88) |
| 1.
Patients may have more than one pretreatment pathogen. 2. n=number of patients with satisfactory response. 3. N=number of patients in the clinically evaluable population or subgroup within treatment groups. 4. %= Percent of satisfactory clinical response at follow-up evaluation. |
||
The proportion of patients who discontinued study treatment due to an adverse event was similar for both treatment groups (meropenem, 2.5% and imipenem-cilastatin, 2.7%).
One controlled clinical study of complicated intra-abdominal infection was performed in the United States where meropenem was compared with clindamycin/tobramycin. Three controlled clinical studies of complicated intra-abdominal infections were performed in Europe; meropenem was compared with imipenem (two trials) and cefotaxime/metronidazole (one trial).
Using strict evaluability criteria and microbiologic eradication and clinical cures at follow-up which occurred 7 or more days after completion of therapy, the presumptive microbiologic eradication/clinical cure rates and statistical findings are provided in Table 11:
Table 11: Presumptive Microbiologic Eradication and Clinical Cure Rates at Test-of-Cure Visit in the Evaluable Population with Complicated Intra-Abdominal Infection
| Treatment Arm | No. evaluable/ No. enrolled (%) | Microbiologic Eradication Rate | Clinical Cure Rate | Outcome |
| meropenem | 146/516 (28%) | 98/146 (67%) | 101/146 (69%) | |
| imipenem | 65/220 (30%) | 40/65 (62%) | 42/65 (65%) | meropenem equivalent to control |
| cefotaxime/ metronidazole | 26/85 (30%) | 22/26 (85%) | 22/26 (85%) | meropenem not equivalent to control |
| clindamycin/tobramycin | 50/212 (24%) | 38/50 (76%) | 38/50 (76%) | meropenem equivalent to control |
The finding that meropenem was not statistically equivalent to cefotaxime/metronidazole may have been due to uneven assignment of more seriously ill patients to the meropenem arm. Currently there is no additional information available to further interpret this observation.
Four hundred forty-six patients (397 pediatric patients 3 months to less than 17 years of age) were enrolled in 4 separate clinical trials and randomized to treatment with meropenem (n=225) at a dose of 40 mg/kg every 8 hours or a comparator drug, i.e., cefotaxime (n=187) or ceftriaxone (n=34), at the approved dosing regimens. A comparable number of patients were found to be clinically evaluable (ranging from 61-68%) and with a similar distribution of pathogens isolated on initial CSF culture.
Patients were defined as clinically not cured if any one of the following three criteria were met:
Using the definition, the following efficacy rates were obtained, per organism (noted in Table 12). The values represent the number of patients clinically cured/number of clinically evaluable patients, with the percent cure in parentheses.
Table 12: Efficacy rates by Pathogen in the Clinically Evaluable Population with Bacterial Meningitis
| MICROORGANISMS | MERREM IV | COMPARATOR |
| S. pneumoniae | 17/24 (71) | 19/30 (63) |
| H. influenzae (+)1 | 8/10 (80) | 6/6 (100) |
| H. influenzae (-/NT)2 | 44/59 (75) | 44/60 (73) |
| N. meningitidis | 30/35 (86) | 35/39 (90) |
| Total (including others) | 102/131 (78) | 108/140 (77) |
|
1. (+) β-lactamase-producing 2. (-/NT) non-β-lactamase-producing or not tested |
||
Sequelae were the most common reason patients were assessed as clinically not cured.
Five patients were found to be bacteriologically not cured, 3 in the comparator group (1 relapse and 2 patients with cerebral abscesses) and 2 in the meropenem group (1 relapse and 1 with continued growth of Pseudomonas aeruginosa).
With respect to hearing loss, 263 of the 271 evaluable patients had at least one hearing test performed post-therapy. The following table shows the degree of hearing loss between the meropenem-treated patients and the comparator-treated patients.
Table 13: Hearing Loss at Post-Therapy in the Evaluable Population Treated with Meropenem
| Degree of Hearing Loss (in one or both ears) |
Meropenem n = 128 |
Comparator n = 135 |
| No loss | 61% | 56% |
| 20-40 decibels | 20% | 24% |
| Greater than 40-60 decibels | 8% | 7% |
| Greater than 60 decibels | 9% | 10% |
REFERENCES
1. Clinical and Laboratory Standards Institute (CLSI). Methods for Dilution Antimicrobial Susceptibility Tests for Bacteria that Grow Aerobically; Approved Standard -Tenth Edition. CLSI document M07-A10, Clinical and Laboratory Standards Institute, 950 West Valley Road, Suite 2500, Wayne, Pennsylvania 19087, USA, 2015.
2. Clinical and Laboratory Standards Institute (CLSI). Performance Standards for Antimicrobial Disk Diffusion Susceptibility Tests; Approved Standard -Twelfth Edition. CLSI document M02-A12, Clinical and Laboratory Standards Institute, 950 West Valley Road, Suite 2500, Wayne, Pennsylvania 19087, USA, 2015.
3. Clinical and Laboratory Standards Institute (CLSI). Performance Standards for Antimicrobial Susceptibility Testing; Twenty-seventh Informational Supplement, CLSI document M100-S27, Clinical and Laboratory Standards Institute, 950 West Valley Road, Suite 2500, Wayne, Pennsylvania 19087, USA, 2017.
4. Clinical and Laboratory Standards Institute (CLSI). Methods for Antimicrobial Susceptibility Testing of Anaerobic Bacteria; Approved Standard -Eight Edition. CLSI document M11-A8. Clinical and Laboratory Standards Institute, 950 West Valley Road, Suite 2500, Wayne, PA 19087 USA, 2012.
